Lava Lizards

by Todd Metcalfe

Lava Lizards
There are seven different species of Tropidurus, lava lizards, found in the Galápagos. The seven different species are T. grayi, T. bivattatus, T. pacificus, T. habellii,
T. delanonis, T. albemarlensis, and T. duncanensis. According to Michael H. Jackson in his 1993 field guide, "One species occurs on all the central and western islands (which were perhaps connected during periods of lower sea levels), while one species each occurs on the six other more peripheral islands." Evidence supporting the Theory of Evolution is found when observing the lava lizards of different islands. It is believed that all of the different species of lava lizards evolved from one single species.
We saw lava lizards on the following islands, view them to see the differences:

The male lava lizard is larger then the female and they look
distinctly different. The overall color patterns are different, and females have bright red skin under their
throats. The males are territorial and will protect their
territories from other males. They will threaten intruders by doing "push-ups"
(video of lava lizard push up coming soon.)

The food chain for these lizards is not very complex.
Lava lizards are omnivores and eat moths, flies, beetles, ants, spiders,
grasshoppers, and some plants. They are eaten by hawks, snakes, mockingbirds, herons, and
centipedes. Besides camouflage, they have one major defense mechanism to help keep
them from joining the food chain, by being eaten by a higher animal: they will "drop"
their tail when a predator grabs hold of it. The dropped piece of tail will continue to
move about while the lizard attempts to flee. Click here to see
a lava lizard with a new tail growing in. A new tail will grow back to replace the old tail.
This defense mechanism allow these lizards to live up to ten years.
Sometimes the tail will grow back wrong. Click here to see the two tailed lizard that we saw.